1. Field of the Invention
The present invention relates to television systems, and more specifically to a method and apparatus for reducing flicker in the combined display of television signals and network application data on a television display screen.
2. Related Art
Since the 1940s, television systems have been increasingly embraced by many households, particularly in the industrial countries. Television systems have generally been used to view broadcasts made in distant parts of the world or to view a pre-recorded program from a video cassette player (VCP). A significant proportion of the households presently have at least one television set in their homes. Television displays are presently available or anticipated to be widely available in analog (e.g., NTSC analog signal displayed on a CRT based display screen) as well as digital technologies (e.g., HDTV).
In parallel, data network applications (hereafter "network applications") have experienced a phenomenal growth since the mid-1980s. Network applications such as web-browsing and electronic mail have had a fundamental impact on the manner in which information is exchanged and disseminated. These network applications have particularly been implemented for and used along with computer systems such as personal computer systems, work-stations, and the like.
At least in view of the considerable presence of the television systems in the households, it may be desirable to provide the capability to access the network applications on television systems. However, there may be several problems which need to be addressed to enable access of data network applications from television systems.
For example, the system may need to be designed to appropriately process the different forms/formats in which the signals of the network applications and television signal are received. As is well known, a television signal may be received in an interlaced format (e.g., composite television signal in NTSC format) and the network application data may be received in a non-interlaced format.
In addition, network application data may be characterized by sharp transitions in color (e.g., the display may include alternative scan lines of black and white). In general, the display of such transitions on television screens results in flicker. As is well known in the art, flicker on television displays is undesirable as it can cause considerable strain on human eyes.
Thus, what is needed is a method and apparatus which can display both the interlaced television signal and the non-interlaced data network application data on a television display screen while reducing or eliminating flicker in the network application data display.